Lalit Kumar BMessages: 3122Registered: May 2013 Location: World Wide on the Web

Senior Member

It is more important to know the number of blocks for which the parallel read occured. It will be displayed in the sql trace. Just by looking at the time elapsed, nothing much can be concluded about the I/O latency.

2. As you can see in TKPROF - the query retrieves 414820 entries via INDEX RANGE SCAN on IDX_USER_INDEX, but only 7426 from the table itself.
There is probably filtering on the other WHERE conditions. You can try index :